Rocker arm with lubrication provisions

ABSTRACT

A cold-formed rocker arm with unique lubrication provisions is disclosed. The rocker arm includes a one-piece metal body of generally inverted U-shaped cross section having a top wall and two side walls. One end of the body has a recess to engage an end of a push rod and the other end has a large, upwardly-facing recess to retain oil so as to provide lubrication substantially immediately when the engine is started. The bottom surface of the reservoir forms a pad to engage an end of a valve stem. A mounting bolt of the rocker arm has a splash ring on the head thereof to disperse oil when intercepting a stream thereof.

This invention relates to a cold-formed rocker arm having a large upperoil reservoir and a mounting bolt with a splash ring.

The rocker arm in accordance with the invention includes a one-piecemetal body which is of inverted U-shaped cross section throughout mostof its length. The body has a top wall with two structurally-integralside walls depending therefrom. One end portion of the rocker arm bodyhas a recess formed therein and facing downwardly to receive an upperend of a push rod and has a slanted oil port directed upwardly toward anintermediate portion of the rocker arm. A second end portion of therocker arm body has a large upwardly-facing recess in the top wallforming a large oil reservoir to retain oil when the engine is stopped.An oil passage is formed therein, communicating with a lower surface ofthe top wall below the reservoir, which surface is convex facingdownwardly, and forms a pad to engage an upper end of a valve stem.

The rocker arm body has aligned annular flanges in the side wallsthereof to receive bearings which are mounted on ends of a hub locatedbetween the side walls of the rocker arm. The hub has a transverse borethrough which a mounting bolt extends to support the rocker arm on acylinder head of an internal combustion engine. The mounting bolt has ahead which extends upwardly through an intermediate opening in the topwall of the rocker arm and the head has an outwardly-extending splashring therearound. The splash ring is positioned to intercept a stream oflubricant from the slanted oil port and disperse it, with some beingreceived in the large oil reservoir.

It is, therefore, a principal object of the invention to provide arocker arm with lubricant provisions which supply lubricant to portionsof the rocker arm when an internal combustion engine is started.

Another object of the invention is to provide a rocker arm having alarge oil reservoir in an upper surface thereof.

Yet another object of the invention is to provide a rocker arm of thecold-formed type having an oil reservoir in an end portion thereof witha downwardly-facing convex surface forming a pad to engage a valve stem.

Yet a further object of the invention is to provide a rocker arm havinga mounting bolt with a splash ring thereon positioned to intercept anddisperse a stream of oil.

Still a further object of the invention is to provide a rocker arm witha large oil reservoir to provide lubrication at start up and a mountingbolt with a splash ring to supply oil to the reservoir.

Many other objects and advantages of the invention will be apparent fromthe following detailed description of a preferred embodiment thereof,reference being made to the accompanying drawings, in which:

FIG. 1 is a fragmentary, somewhat schematic side view in elevation of arocker arm assembly in accordance with the invention, mounted on anengine which is shown in cross section;

FIG. 2 is an enlarged view in longitudinal cross section of the rockerarm shown in FIG. 1;

FIG. 3 is a view in transverse cross section taken through a centralportion of the rocker arm of FIG. 2; and

FIG. 4 is a view in perspective of the rocker arm, with a mounting boltshown in dotted lines.

Referring to the drawings, and particularly to FIG. 1, a rocker armassembly in accordance with the invention is indicated at 10 andincludes a cold-formed rocker arm 12 pivotally mounted on a supportingpedestal 14. The supporting pedestal is affixed to a cylinder head 16 ofan engine block. One end of the rocker arm 12 engages a push rod 18through which oil is supplied, and the other end of the rocker armengages a valve stem 20. The valve stem extends upwardly from a valve(not shown) in the cylinder head and through a coiled compression spring22 which is between the cylinder head and a retaining ring 24 mounted onthe valve stem.

Referring more particularly to FIGS. 2-4, the rocker arm 12 includes aone-piece metal body 26 having a top wall 28 and twostructurally-integral side walls 30 and 32 depending therefrom. Centralportions of the side walls 30 and 32 have annular flanges 34 and 36extending outwardly therefrom and being structurally integral therewith.These flanges are stamped or extruded from the side walls 30 and 32 andform aligned bores 38 and 40 (FIG. 3). Outer bearing races 42 are pressfit in the bores and retain rolling elements or needles 44. The mountingpedestal 14 has a hub 46 from which cylindrical extensions 48 extend,forming inner races for the bearing elements. Ends of the extensions 48have annular grooves 50 which hold suitable snap rings 52 which restrictaxially movement of the outer races 42. A mounting post 54 fits closelywith a lower surface of the hub 46 and supports the rocker arm assemblyabove the upper surface of the cylindrical head 16. The hub 46 and thepost 54 are held in assembled relationship by a mounting bolt 56 whichextends through bores 58 and 60 in the hub 46 and the mounting post 54.A lower threaded end 62 of the bolt 56 extends through a trough element64 which cooperates with the mounting post 54 to aid in retaining therocker arm assembly 10 in position. The mounting bolt 56 furtherincludes an intermediate shank 66 which extends through the bores 58 and60 and an enlarged head 68 which extends through an elongate, generallyrectangular intermediate opening 70 in an intermediate portion of thetop wall 28 of the rocker arm body 26. The upper end of the enlargedhead 68 of the mounting bolt 56 above the top wall 28 has anoutwardly-extending splash ring 72 thereon in accordance with theinvention.

The splash ring 72 is positioned to receive a stream of oil issuing froma slanted oil port 74 at one end of the rocker arm body 26. The supplyport 74 extends through the top wall 28 and communicates with adownwardly-facing recess 76 which is of generally semi-spherical shapeand engages a rounded upper end 78 (FIG. 1) of the push rod 18. Oilsupplied through the push rod 18 is directed by the port 74 toward thesplash ring 72 and is intercepted and dispersed by the splash ring.

A portion of the oil dispersed by the splash ring is received in a largeoil reservoir 80 which is formed at an end portion of the top wall 28opposite the recess 76. The reservoir 80 is formed by an upwardly-facingrecess stamped in the top wall 28 which also forms a downwardly-facingconvex surface or pad 82 on the underside of the top wall 28. The pad 82engages an upper end 84 (FIG. 1) of the valve stem 20. One stampingoperation thus forms both the large oil reservoir 80 and the valve stempad 82. An oil passage 86 (FIGS. 2 and 4) extends through the top wall28 to supply oil from the reservoir 80 to the pad 82 almost immediatelywhen the engine is started to minimize wear of the components. The oilpassage 86 is located near an upper shallow end portion of the reservoir80 so that oil will be retained in the reservoir 80 regardless of theposition of the rocker arm 12 when the engine is stopped. Further, thereservoir 80 is wide toward the end of the rocker arm body 26 to providegreater oil capacity. The reservoir is also narrower toward the oilpassage 86 to more effectively direct oil into the passage 86. Thereservoir 80 is large enough to supply oil to the pad 82 for aboutfifteen to twenty seconds when the engine is first started.

Various modifications of the above-described embodiment of the inventionwill be apparent to those skilled in the art, and it is to be understoodthat such modifications can be made without departing from the scope ofthe invention, if they are within the spirit and the tenor of theaccompanying claims.

We claim:
 1. A cold-formed rocker arm comprising a onepiece metal bodyof generally inverted U-shaped cross section throughout most of itslength, said body having a top wall and two side walls extendingdownwardly therefrom and being integral therewith, said side wallshaving annular flanges extending outwardly therefrom and forming alignedbores to receive bearings, said body having means at one end to engagean end of a push rod, and said body having an upwardly-facing recess inthe top wall at the other end thereof, the bottom surface of said topwall below said recess forming a pad to engage an end of a valve stem,said recess having a shallow portion and a deeper portion, said deeperportion being closer to said other end than said shallow portion, saidtop wall having a lubrication passage extending therethroughcommunicating with said shallow portion of said recess and with saidpad, with oil being retained at least in said deeper portion for anyposition the rocker arm is in when the engine is stopped.
 2. Acold-formed rocker arm according to claim 1 wherein said rocker arm hasa mounting hub with bearings at the ends thereof located in said annularflanges, said mounting hub having a central bore therethrough, said topwall having an intermediate opening therein, and a mounting boltextending through said intermediate opening and through said bore insaid mounting hub to pivotally mount said rocker arm on a cylinder headof an internal combustion engine.
 3. A cold-formed rocker arm accordingto claim 2 wherein said bolt has an annular flange extending outwardlytherefrom above said top wall of said rocker arm to provide alubrication splash plate for said rocker arm.
 4. A cold-formed rockerarm according to claim 3 wherein said means to engage an end of a pushrod has an oil port extending through said top wall and aligned withsaid splash plate to direct oil toward said splash plate.
 5. Acold-formed rocker arm for an internal combustion engine, said rockerarm comprising a one-piece metal body of generally inverted U-shapedcross section throughout most of its length, said body having a top walland two side walls extending downwardly therefrom, said body havingmeans at one end portion to engage an end of a push rod, said bodyhaving means at the other end portion to engage an end of a valve stem,said body having an upwardly-facing recess at said other end portion toprovide an oil reservoir for supplying oil to said last-named means whenthe engine is started, and said body having a lubrication passagecommunicating with said means to engage the end of the valve stem andwith said recess, said recess having a shallow portion and a deeperportion, said passage communicating with the shallow portion of saidrecess, the deeper portion of said recess retaining oil therein for anyposition of the rocker arm.
 6. A cold-formed rocker arm according toclaim 5 wherein said rocker arm has a mounting hub located between saidside walls of said body, said mounting hub having a central boretherethrough, and a mounting bolt extending through said bore and abovesaid top wall, said bolt having a splash plate extending outwardlytherefrom above said top wall.
 7. A cold-formed rocker arm according toclaim 6 wherein said body has an oil port therein for directing oiltoward said splash plate.
 8. A cold-formed rocker arm according to claim7 wherein said means for engaging the upper end of the push rod is adownwardly-facing recess and said oil port communicates with saiddownwardly-facing recess.
 9. A cold-formed rocker arm comprising aonepiece metal body of generally inverted U-shaped cross sectionthroughout most of its length, said body having a top wall and two sidewalls extending downwardly therefrom and being structurally integraltherewith, said body having means at one end portion to engage an end ofa push rod, said body having an upwardly-facing recess in an uppersurface of the top wall toward the other end of said body, said bodyforming a downwardly-facing pad on a lower surface of the top wall toengage an end of a valve stem, said top wall being of substantiallyuniform thickness between said upper and lower surfaces forming saidrecess and said pad, said body having a lubrication passagecommunicating with said pad and with said recess, said top wall havingan intermediate opening therein, a mounting hub between intermediateportions of said side walls of said body, said mounting hub having acentral bore therethrough, and a mounting bolt extending through saidcentral bore and through said intermediate opening, said bolt having asplash place above said top wall of said body.
 10. A cold-formed rockerarm according to claim 9 wherein said recess has a shallow portion and adeeper portion and said passage communicates with the shallow portion ofsaid recess.